When several wireless communication systems are available, such as High Frequency (HF) transmission systems, Ultra High Frequency (UHF), satellite transmission systems or microwave high data rate transmission systems such as the WIMAX (Worldwide Interoperability for Microwave Access) system, the problem arises of the selection of a communication link for conveying the data packets that it is desired to transmit to this link. Specifically, these various systems have specific characteristics and the communication requirements, notably in terms of data rate and of quality of service, may differ depending on the user or the type of messages transmitted. For a given application, for example a video conferencing, audio conferencing or electronic mail application, the data rate requirements and the constraints concerning latency of the transmission are not the same. Intrinsically, the transmission of video content requires a higher data rate than that necessary for simply sending text messages. Similarly, a conversational application will require a low latency unlike an application for broadcasting audio or video content.
For these reasons, it is important to use an automatic method for selecting the medium most suitable for the requirements of the user and also taking account of the availability of each medium which may be congested by an application using the whole data rate resource available or suffering interference from difficult propagation conditions.
One of the problems that the invention seeks to solve is to make automatic the selection of the type of transmission medium as a function of the communication requirements. In the naval context, a known solution consists in using a human decision, by means of a radio operator, to take the decision. In practice, this radio operator configures a matrix of connections which link, at a given moment, a user to the transmission medium that is most operational and that best satisfies the requirements of the user.
This solution has the major drawback of being not very effective because it is not automatic and requires a constant updating of circuits which link the terminals to each wireless communication system.
Other solutions for the automatic routing of the transmitted packets exist but they do not take account of the characteristics of each communication system and of each transmission medium in order to offer the best performance in terms of quality of service for a user and a given application.
In the rest of the description, the term transmission medium is used to designate the physical link between the source and the destination of a packet and more particularly a wireless link. The terms transmission systems and communication resources designate the items of transceiver equipment used to transmit data over a transmission medium.
The present invention proposes a solution of automatic selection of the most appropriate communication resources as a function of various criteria such as the type of application, the type of user, the availability of the transmission medium, its data rate and its latency.
A notable advantage of the invention is that it makes it possible to exploit all the available communication resources and to distribute them in the best way depending on the requirements and the priorities. It also allows compatibility with the network architectures based on the IP (Internet Protocol) communication protocol.